ejemplo conexión mongo con mongoose y nodejs

index.js

const mongoose = require('mongoose');

(async()=>{
  await mongoose.connect('mongodb://nodeco-test-user:nodecotest1234@ds163822.mlab.com:63822/nodeco-test-01-mayo', {
    useNewUrlParser: true,
    useUnifiedTopology: true
  });
})()


const Schema = mongoose.Schema;
const ObjectId = Schema.ObjectId;
 
const BlogPost = new Schema({
  title: String,
  body: String,
  date: Date
});

const BlogPostModel = mongoose.model('blospost', BlogPost);


const blogPost = new BlogPostModel({
  title: 'titulo2',
  body: 'esto es un blog post 222222',
  date: new Date()
});

(async ()=>{
  await blogPost.save(); // espera a guardar el documento
  await mongoose.disconnect(); // cierra la conexion
})()